1. Field of the Invention
The present invention is related generally to a low pressure heater control system and more specifically to an apparatus and method for flame and fuel recognition and analysis for low pressure liquid fueled heaters.
2. Description of Related Art
Low pressure liquid fueled heaters typically include at least a fuel tank, a combustion chamber, a compressor, a fuel nozzle assembly, and an igniter. Compressed air moving through the fuel nozzle assembly creates suction on a fuel line that runs from the fuel nozzle assembly to the fuel tank. The suction draws one of a multitude of usable fuels from the fuel tank into the fuel nozzle assembly and the compressed air delivers the fuel through the nozzle and causes it to be atomized and expelled through the nozzle output and delivered into the combustion chamber in the vicinity of the igniter, where it is ignited. The igniter may be a spark plug, glow plug, hot surface igniter, or the like. The fan typically provides secondary combustion air to the combustion chamber and also serves to discharge the heated air through a discharge end of the combustion chamber.
Optical sensors and other sensors have been used with electronic controls in low pressure liquid fueled heaters to monitor characteristics of a flame burning in a low pressure liquid fueled heater combustion chamber. However, prior art electronic controls have struggled to accurately recognize what fuel is being burned and accurately recognize changes in flame characteristics over the entire range of fuel tank levels.